checkpatch: whine about ACCESS_ONCE (481aea5c) · Commits · 戴 / test

Add a test for use of ACCESS_ONCE that could be written using READ_ONCE or WRITE_ONCE. --fix it too if desired. The WRITE_ONCE fixes are less correct than the coccinelle script below as checkpatch cannot have a completely correct "expression" mechanism because checkpatch works on patches and not complete files. $ cat access_once.cocci @@ expression e1; expression e2; @@ - ACCESS_ONCE(e1) = e2 + WRITE_ONCE(e1, e2) @@ expression e1; @@ - ACCESS_ONCE(e1) + READ_ONCE(e1) Signed-off-by:

Joe Perches <joe@perches.com> Cc: Julia Lawall <julia.lawall@lip6.fr> Signed-off-by:

Andrew Morton <akpm@linux-foundation.org> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

scripts/checkpatch.pl

+22 −0

Original line number	Diff line number	Diff line
		@@ -5850,6 +5850,28 @@ sub process {
		}
		}

		# whine about ACCESS_ONCE
		if ($^V && $^V ge 5.10.0 &&
		$line =~ /\bACCESS_ONCE\s$balanced_parens\s(=(?!=))?\s*($FuncArg)?/) {
		my $par = $1;
		my $eq = $2;
		my $fun = $3;
		$par =~ s/^$\s(.)\s*$$/$1/;
		if (defined($eq)) {
		if (WARN("PREFER_WRITE_ONCE",
		"Prefer WRITE_ONCE(<FOO>, <BAR>) over ACCESS_ONCE(<FOO>) = <BAR>\n" . $herecurr) &&
		$fix) {
		$fixed[$fixlinenr] =~ s/\bACCESS_ONCE\s$\s\Q$par\E\s$\s$eq\s*\Q$fun\E/WRITE_ONCE($par, $fun)/;
		}
		} else {
		if (WARN("PREFER_READ_ONCE",
		"Prefer READ_ONCE(<FOO>) over ACCESS_ONCE(<FOO>)\n" . $herecurr) &&
		$fix) {
		$fixed[$fixlinenr] =~ s/\bACCESS_ONCE\s$\s\Q$par\E\s*$/READ_ONCE($par)/;
		}
		}
		}

		# check for lockdep_set_novalidate_class
		if ($line =~ /^.\slockdep_set_novalidate_class\s\(/ \|\|
		$line =~ /__lockdep_no_validate__\s*\)/ ) {

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